#!/usr/bin/env ruby

#--
# Copyright (c) 2003, 2004, 2005, 2006 Jim Weirich
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#++
#
# = Rake -- Ruby Make
# 
# This is the main file for the Rake application.  Normally it is
# referenced as a library via a require statement, but it can be
# distributed independently as an application.

RAKEVERSION = '0.7.1'

require 'rbconfig'
require 'ftools'
require 'getoptlong'
require 'fileutils'
require 'singleton'
require 'thread'
require 'ostruct'

# Some objects are dupable, some are not.  So we define a version of
# dup (called rake_dup) that returns self on the handful of classes
# that are not dupable.

module Kernel
  # Duplicate an object if it can be duplicated.  If it can not be
  # cloned or duplicated, then just return the original object.
  def rake_dup()
    dup
  end
end

[NilClass, FalseClass, TrueClass, Fixnum, Symbol].each do |clazz|
  clazz.class_eval {
    # Duplicate an object if it can be duplicated.  If it can not be
    # cloned or duplicated, then just return the original object.
    def rake_dup() self end
  }
end

######################################################################
# User defined methods to be added to String.
#
class String
  unless instance_methods.include? "ext"
    # Replace the file extension with +newext+.  If there is no
    # extenson on the string, append the new extension to the end.  If
    # the new extension is not given, or is the empty string, remove
    # any existing extension.
    #
    # +ext+ is a user added method for the String class.
    def ext(newext='')
      return self.dup if ['.', '..'].include? self
      if newext != ''
 	newext = (newext =~ /^\./) ? newext : ("." + newext)
      end
      dup.sub!(%r(([^/\\])\.[^./\\]*$)) { $1 + newext } || self + newext
    end
  end


  unless instance_methods.include? "pathmap" 
    # Explode a path into individual components.  Used by +pathmap+.
    def pathmap_explode
      head, tail = File.split(self)
      return [self] if head == self
      return [tail] if head == '.' || tail == '/'
      return [head, tail] if head == '/'
      return head.pathmap_explode + [tail]
    end
    protected :pathmap_explode

    # Extract a partial path from the path.  Include +n+ directories
    # from the front end (left hand side) if +n+ is positive.  Include
    # |+n+| directories from the back end (right hand side) if +n+ is
    # negative.
    def pathmap_partial(n)
      target = File.dirname(self)
      dirs = target.pathmap_explode
      if n > 0
        File.join(dirs[0...n])
      elsif n < 0
        partial = dirs[n..-1]
        if partial.nil? || partial.empty?
          target
        else
          File.join(partial)
        end
      else
        "."
      end
    end
    protected :pathmap_partial

    # Preform the pathmap replacement operations on the given path.
    # The patterns take the form 'pat1,rep1;pat2,rep2...'.
    def pathmap_replace(patterns, &block)
      result = self
      patterns.split(';').each do |pair|
        pattern, replacement = pair.split(',')
        pattern = Regexp.new(pattern)
        if replacement == '*' && block_given?
          result = result.sub(pattern, &block)
        elsif replacement
          result = result.sub(pattern, replacement)
        else
          result = result.sub(pattern, '')
        end
      end
      result
    end
    protected :pathmap_replace

    # Map the path according to the given specification.  The
    # specification controls the details of the mapping.  The
    # following special patterns are recognized:
    #
    # * <b>%p</b> -- The complete path.   
    # * <b>%f</b> -- The base file name of the path, with its file
    #   extension, but without any directories.
    # * <b>%n</b> -- The file name of the path without its file
    #   extension.
    # * <b>%d</b> -- The directory list of the path.
    # * <b>%x</b> -- The file extension of the path.  An empty string
    #   if there is no extension.
    # * <b>%X</b> -- Everything *but* the file extension.
    # * <b>%s</b> -- The alternate file separater if defined,
    #   otherwise use the standard file separator.
    # # <b>%%</b> -- A percent sign.
    #
    # The %d specifier can also have a numeric prefix (e.g. '%2d').
    # If the number is positive, only return (up to) +n+ directories
    # in the path, starting from the left hand side.  If +n+ is
    # negative, return (up to) |+n+| directories from the right hand
    # side of the path.
    #
    # Examples:
    #
    #   'a/b/c/d/file.txt'.pathmap("%2d")   => 'a/b'
    #   'a/b/c/d/file.txt'.pathmap("%-2d")  => 'c/d'
    #
    # Also the %d, %p, $f, $n, %x, and %X operators can take a
    # pattern/replacement argument to perform simple string
    # substititions on a particular part of the path.  The pattern and
    # replacement are speparated by a comma and are enclosed by curly
    # braces.  The replacement spec comes after the % character but
    # before the operator letter.  (e.g. "%{old,new}d").  Muliple
    # replacement specs should be separated by semi-colons
    # (e.g. "%{old,new;src,bin}d").
    #
    # Regular expressions may be used for the pattern, and back refs
    # may be used in the replacement text.  Curly braces, commas and
    # semi-colons are excluded from both the pattern and replacement
    # text (let's keep parsing reasonable).
    #
    # For example: 
    #
    #    "src/org/onestepback/proj/A.java".pathmap("%{^src,bin}X.class")
    # 
    # returns:
    #
    #    "bin/org/onestepback/proj/A.class"
    #
    # If the replacement text is '*', then a block may be provided to
    # perform some arbitrary calculation for the replacement.
    #
    # For example:
    #
    #   "/path/to/file.TXT".pathmap("%X%{.*,*}x") { |ext|
    #      ext.downcase
    #   }
    #
    # Returns:
    #
    #  "/path/to/file.txt"
    #
    def pathmap(spec=nil, &block)
      return self if spec.nil?
      result = ''
      spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
        case frag
        when '%f'
          result << File.basename(self)
        when '%n'
          result << File.basename(self).ext
        when '%d'
          result << File.dirname(self)
        when '%x'
          result << $1 if self =~ /[^\/](\.[^.]+)$/
        when '%X'
          if self =~ /^(.+[^\/])(\.[^.]+)$/
            result << $1
          else
            result << self
          end
        when '%p'
          result << self
        when '%s'
          result << (File::ALT_SEPARATOR || File::SEPARATOR)
        when '%%'
          result << "%"
        when /%(-?\d+)d/
          result << pathmap_partial($1.to_i)
        when /^%\{([^}]*)\}(\d*[dpfnxX])/
          patterns, operator = $1, $2
          result << pathmap('%' + operator).pathmap_replace(patterns, &block)
        when /^%/
          fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
        else
          result << frag
        end
      end
      result
    end
  end
end

######################################################################
module Rake

  # ------------------------------------------------------------------
  # Rake module singleton methods.
  #
  class << self
    # Current Rake Application
    def application
      @application ||= Rake::Application.new
    end

    # Set the current Rake application object.
    def application=(app)
      @application = app
    end

    # Return the original directory where the Rake application was
    # started.
    def original_dir
      application.original_dir
    end

  end

  ####################################################################
  # Mixin for creating easily cloned objects.
  #
  module Cloneable
    # Clone an object by making a new object and setting all the
    # instance variables to the same values.
    def clone
      sibling = self.class.new
      instance_variables.each do |ivar|
        value = self.instance_variable_get(ivar)
        sibling.instance_variable_set(ivar, value.rake_dup)
      end
      sibling
    end
    alias dup clone
  end
end

module Rake

  ######################################################################
  # A Task is the basic unit of work in a Rakefile.  Tasks have
  # associated actions (possibly more than one) and a list of
  # prerequisites.  When invoked, a task will first ensure that all of
  # its prerequisites have an opportunity to run and then it will
  # execute its own actions.
  #
  # Tasks are not usually created directly using the new method, but
  # rather use the +file+ and +task+ convenience methods.
  #
  class Task
    # List of prerequisites for a task.
    attr_reader :prerequisites

    # Application owning this task.
    attr_accessor :application
    
    # Comment for this task.
    attr_accessor :comment
    
    # Array of nested namespaces names used for task lookup by this task.
    attr_reader :scope

    # Return task name
    def to_s
      name
    end
    
    # List of sources for task.
    attr_writer :sources
    def sources
      @sources ||= []
    end

    # First source from a rule (nil if no sources)
    def source
      @sources.first if defined?(@sources)
    end
    
    # Create a task named +task_name+ with no actions or prerequisites..
    # use +enhance+ to add actions and prerequisites.
    def initialize(task_name, app)
      @name = task_name.to_s
      @prerequisites = FileList[]
      @actions = []
      @already_invoked = false
      @comment = nil
      @lock = Mutex.new
      @application = app
      @scope = app.current_scope
    end
    
    # Enhance a task with prerequisites or actions.  Returns self.
    def enhance(deps=nil, &block)
      @prerequisites |= deps if deps
      @actions << block if block_given?
      self
    end
    
    # Name of the task, including any namespace qualifiers.
    def name
      @name.to_s
    end
    
    # Invoke the task if it is needed.  Prerequites are invoked first.
    def invoke
      @lock.synchronize do
	if application.options.trace
	  puts "** Invoke #{name} #{format_trace_flags}"
	end
	return if @already_invoked
	@already_invoked = true
	invoke_prerequisites
	execute if needed?
      end
    end

    # Invoke all the prerequisites of a task.
    def invoke_prerequisites
      @prerequisites.each { |n|
	application[n, @scope].invoke
      }
    end

    # Format the trace flags for display.
    def format_trace_flags
      flags = []
      flags << "first_time" unless @already_invoked
      flags << "not_needed" unless needed?
      flags.empty? ? "" : "(" + flags.join(", ") + ")"
    end
    private :format_trace_flags
    
    # Execute the actions associated with this task.
    def execute
      if application.options.dryrun
	puts "** Execute (dry run) #{name}"
	return
      end
      if application.options.trace
	puts "** Execute #{name}"
      end
      application.enhance_with_matching_rule(name) if @actions.empty?
      @actions.each { |act| result = act.call(self) }
    end
    
    # Is this task needed?
    def needed?
      true
    end
    
    # Timestamp for this task.  Basic tasks return the current time for
    # their time stamp.  Other tasks can be more sophisticated.
    def timestamp
      @prerequisites.collect { |p| Rake::Task[p].timestamp }.max || Time.now
    end
    
    # Add a comment to the task.  If a comment alread exists, separate
    # the new comment with " / ".
    def add_comment(comment)
      return if ! comment
      if @comment 
	@comment << " / "
      else
	@comment = ''
      end
      @comment << comment
    end
    
    # Return a string describing the internal state of a task.  Useful
    # for debugging.
    def investigation
      result = "------------------------------\n"
      result << "Investigating #{name}\n" 
      result << "class: #{self.class}\n"
      result <<  "task needed: #{needed?}\n"
      result <<  "timestamp: #{timestamp}\n"
      result << "pre-requisites: \n"
      prereqs = @prerequisites.collect {|name| Rake::Task[name]}
      prereqs.sort! {|a,b| a.timestamp <=> b.timestamp}
      prereqs.each do |p|
	result << "--#{p.name} (#{p.timestamp})\n"
      end
      latest_prereq = @prerequisites.collect{|n| Rake::Task[n].timestamp}.max
      result <<  "latest-prerequisite time: #{latest_prereq}\n"
      result << "................................\n\n"
      return result
    end
    
    # ----------------------------------------------------------------
    # Rake Module Methods
    #    
    class << self
      
      # Clear the task list.  This cause rake to immediately forget all
      # the tasks that have been assigned.  (Normally used in the unit
      # tests.)
      def clear
	Rake.application.clear
      end
      
      # List of all defined tasks.
      def tasks
	Rake.application.tasks
      end
      
      # Return a task with the given name.  If the task is not currently
      # known, try to synthesize one from the defined rules.  If no
      # rules are found, but an existing file matches the task name,
      # assume it is a file task with no dependencies or actions.
      def [](task_name)
	Rake.application[task_name]
      end
      
      # TRUE if the task name is already defined.
      def task_defined?(task_name)
	Rake.application.lookup(task_name) != nil
      end
      
      # Define a task given +args+ and an option block.  If a rule with
      # the given name already exists, the prerequisites and actions are
      # added to the existing task.  Returns the defined task.
      def define_task(args, &block)
	Rake.application.define_task(self, args, &block)
      end
      
      # Define a rule for synthesizing tasks.  
      def create_rule(args, &block)
	Rake.application.create_rule(args, &block)
      end

      # Apply the scope to the task name according to the rules for
      # this kind of task.  Generic tasks will accept the scope as
      # part of the name.
      def scope_name(scope, task_name)
	(scope + [task_name]).join(':')
      end

    end
  end
  
  
  ######################################################################
  # A FileTask is a task that includes time based dependencies.  If
  # any of a FileTask's prerequisites have a timestamp that is later
  # than the file represented by this task, then the file must be
  # rebuilt (using the supplied actions).
  #
  class FileTask < Task
    
    # Is this file task needed?  Yes if it doesn't exist, or if its time
    # stamp is out of date.
    def needed?
      return true unless File.exist?(name)
      return true if out_of_date?(timestamp)
      false
    end
    
    # Time stamp for file task.
    def timestamp
      if File.exist?(name)
	File.mtime(name.to_s)
      else
	Rake::EARLY
      end
    end

    private

    # Are there any prerequisites with a later time than the given
    # time stamp?
    def out_of_date?(stamp)
      @prerequisites.any? { |n| Rake::Task[n].timestamp > stamp}
    end

    # ----------------------------------------------------------------
    # Task class methods.
    #
    class << self
      # Apply the scope to the task name according to the rules for
      # this kind of task.  File based tasks ignore the scope when
      # creating the name.
      def scope_name(scope, task_name)
	task_name
      end
    end
  end
  
  ######################################################################
  # A FileCreationTask is a file task that when used as a dependency
  # will be needed if and only if the file has not been created.  Once
  # created, it is not re-triggered if any of its dependencies are
  # newer, nor does trigger any rebuilds of tasks that depend on it
  # whenever it is updated.
  class FileCreationTask < FileTask
    # Is this file task needed?  Yes if it doesn't exist.
    def needed?
      ! File.exist?(name)
    end
    
    # Time stamp for file creation task.  This time stamp is earlier
    # than any other time stamp.
    def timestamp
      Rake::EARLY
    end
  end

  ####################################################################
  # Same as a regular task, but the immediate prerequisites are done
  # in parallel using Ruby threads.
  #
  class MultiTask < Task
    def invoke_prerequisites
      threads = @prerequisites.collect { |p|
	Thread.new(p) { |r| Task[r].invoke }
      }
      threads.each { |t| t.join }
    end
  end
end

######################################################################
# Task Definition Functions ...

# Declare a basic task.
#
# Example:
#   task :clobber => [:clean] do
#     rm_rf "html"
#   end
#
def task(args, &block)
  Rake::Task.define_task(args, &block)
end


# Declare a file task.
#
# Example:
#   file "config.cfg" => ["config.template"] do
#     open("config.cfg", "w") do |outfile|
#       open("config.template") do |infile|
#         while line = infile.gets
#           outfile.puts line
#         end
#       end
#     end
#  end
#
def file(args, &block)
  Rake::FileTask.define_task(args, &block)
end

# Declare a file creation task.
# (Mainly used for the directory command).
def file_create(args, &block)
  Rake::FileCreationTask.define_task(args, &block)
end

# Declare a set of files tasks to create the given directories on
# demand.
#
# Example:
#   directory "testdata/doc"
#
def directory(dir)
  Rake.each_dir_parent(dir) do |d|
    file_create d do |t|
      mkdir_p t.name if ! File.exist?(t.name)
    end
  end
end

# Declare a task that performs its prerequisites in parallel.
# Multitasks does *not* guarantee that its prerequisites will execute
# in any given order (which is obvious when you think about it)
#
# Example:
#   multitask :deploy => [:deploy_gem, :deploy_rdoc]
#
def multitask(args, &block)
  Rake::MultiTask.define_task(args, &block)
end

# Create a new rake namespace and use it for evaluating the given
# block. Returns a NameSpace object that can be used to lookup tasks
# defined in the namespace.
#
# E.g.
#
#   ns = namespace "nested" do
#     task :run
#   end
#   task_run = ns[:run] # find :run in the given namespace.
#
def namespace(name=nil, &block)
  Rake.application.in_namespace(name, &block)
end

# Declare a rule for auto-tasks.
#
# Example:
#  rule '.o' => '.c' do |t|
#    sh %{cc -o #{t.name} #{t.source}}
#  end
#
def rule(args, &block)
  Rake::Task.create_rule(args, &block)
end

# Describe the next rake task.
#
# Example:
#   desc "Run the Unit Tests"
#   task :test => [:build]
#     runtests
#   end
#
def desc(comment)
  Rake.application.last_comment = comment
end

# Import the partial Rakefiles +fn+.  Imported files are loaded
# _after_ the current file is completely loaded.  This allows the
# import statement to appear anywhere in the importing file, and yet
# allowing the imported files to depend on objects defined in the
# importing file.
#
# A common use of the import statement is to include files containing
# dependency declarations.
#
# See also the --rakelibdir command line option.
#
# Example:
#   import ".depend", "my_rules"
#
def import(*fns)
  fns.each do |fn|
    Rake.application.add_import(fn)
  end
end

######################################################################
# This a FileUtils extension that defines several additional commands
# to be added to the FileUtils utility functions.
#
module FileUtils
  RUBY = File.join(Config::CONFIG['bindir'], Config::CONFIG['ruby_install_name'])

  OPT_TABLE['sh']  = %w(noop verbose)
  OPT_TABLE['ruby'] = %w(noop verbose)

  # Run the system command +cmd+. If multiple arguments are given
  # the command is not run with the shell (same semantics as
  # Kernel::exec and Kernel::system).
  #
  # Example:
  #   sh %{ls -ltr}
  #
  #   sh 'ls', 'file with spaces'
  #
  #   # check exit status after command runs
  #   sh %{grep pattern file} do |ok, res|
  #     if ! ok
  #       puts "pattern not found (status = #{res.exitstatus})"
  #     end
  #   end
  #
  def sh(*cmd, &block)
    if Hash === cmd.last then
      options = cmd.pop
    else
      options = {}
    end
    unless block_given?
      show_command = cmd.join(" ")
      show_command = show_command[0,42] + "..." if show_command.length > 45
      block = lambda { |ok, status|
        ok or fail "Command failed with status (#{status.exitstatus}): [#{show_command}]"
      }
    end
    fu_check_options options, :noop, :verbose
    fu_output_message cmd.join(" ") if options[:verbose]
    unless options[:noop]
      res = system(*cmd)      
      block.call(res, $?)
    end
  end

  # Run a Ruby interpreter with the given arguments.
  #
  # Example:
  #   ruby %{-pe '$_.upcase!' <README}
  #
  def ruby(*args,&block)
    if Hash === args.last
      options = args.pop
    else
      options = {}
    end
    if args.length > 1 then
      sh(*([RUBY] + args + [options]), &block)
    else
      sh("#{RUBY} #{args}", options, &block)
    end
  end
  
  LN_SUPPORTED = [true]

  #  Attempt to do a normal file link, but fall back to a copy if the
  #  link fails.
  def safe_ln(*args)
    unless LN_SUPPORTED[0]
      cp(*args)
    else
      begin
        ln(*args)
      rescue StandardError, NotImplementedError
        LN_SUPPORTED[0] = false
        cp(*args)
      end
    end
  end

  # Split a file path into individual directory names.
  #
  # Example:
  #   split_all("a/b/c") =>  ['a', 'b', 'c']
  #
  def split_all(path)
    head, tail = File.split(path)
    return [tail] if head == '.' || tail == '/'
    return [head, tail] if head == '/'
    return split_all(head) + [tail]
  end
end

######################################################################
# RakeFileUtils provides a custom version of the FileUtils methods
# that respond to the <tt>verbose</tt> and <tt>nowrite</tt> commands.
#
module RakeFileUtils
  include FileUtils

  class << self
    attr_accessor :verbose_flag, :nowrite_flag
  end
  RakeFileUtils.verbose_flag = true
  RakeFileUtils.nowrite_flag = false
  
  $fileutils_verbose = true
  $fileutils_nowrite = false
  
  FileUtils::OPT_TABLE.each do |name, opts|
    default_options = []
    if opts.include?('verbose')
      default_options << ':verbose => RakeFileUtils.verbose_flag'
    end
    if opts.include?('noop')
      default_options << ':noop => RakeFileUtils.nowrite_flag'
    end

    next if default_options.empty?
    module_eval(<<-EOS, __FILE__, __LINE__ + 1)
    def #{name}( *args, &block )
      super(
	*fu_merge_option(args,
	  #{default_options.join(', ')}
	  ), &block)
    end
    EOS
  end

  # Get/set the verbose flag controlling output from the FileUtils
  # utilities.  If verbose is true, then the utility method is echoed
  # to standard output.
  #
  # Examples:
  #    verbose              # return the current value of the verbose flag
  #    verbose(v)           # set the verbose flag to _v_.
  #    verbose(v) { code }  # Execute code with the verbose flag set temporarily to _v_.
  #                         # Return to the original value when code is done.
  def verbose(value=nil)
    oldvalue = RakeFileUtils.verbose_flag
    RakeFileUtils.verbose_flag = value unless value.nil?
    if block_given?
      begin
        yield
      ensure
        RakeFileUtils.verbose_flag = oldvalue
      end
    end
    RakeFileUtils.verbose_flag
  end

  # Get/set the nowrite flag controlling output from the FileUtils
  # utilities.  If verbose is true, then the utility method is echoed
  # to standard output.
  #
  # Examples:
  #    nowrite              # return the current value of the nowrite flag
  #    nowrite(v)           # set the nowrite flag to _v_.
  #    nowrite(v) { code }  # Execute code with the nowrite flag set temporarily to _v_.
  #                         # Return to the original value when code is done.
  def nowrite(value=nil)
    oldvalue = RakeFileUtils.nowrite_flag
    RakeFileUtils.nowrite_flag = value unless value.nil?
    if block_given?
      begin
        yield
      ensure
	RakeFileUtils.nowrite_flag = oldvalue
      end
    end
    oldvalue
  end

  # Use this function to prevent protentially destructive ruby code
  # from running when the :nowrite flag is set.
  #
  # Example: 
  #
  #   when_writing("Building Project") do
  #     project.build
  #   end
  #
  # The following code will build the project under normal conditions.
  # If the nowrite(true) flag is set, then the example will print:
  #      DRYRUN: Building Project
  # instead of actually building the project.
  #
  def when_writing(msg=nil)
    if RakeFileUtils.nowrite_flag
      puts "DRYRUN: #{msg}" if msg
    else
      yield
    end
  end

  # Merge the given options with the default values.
  def fu_merge_option(args, defaults)
    if Hash === args.last
      defaults.update(args.last)
      args.pop
    end
    args.push defaults
    args
  end
  private :fu_merge_option

  extend self
  
end

######################################################################
# Include the FileUtils file manipulation functions in the top level
# module, but mark them private so that they don't unintentionally
# define methods on other objects.

include RakeFileUtils
private(*FileUtils.instance_methods(false))

######################################################################
module Rake

  class RuleRecursionOverflowError < StandardError
    def initialize(*args)
      super
      @targets = []
    end

    def add_target(target)
      @targets << target
    end

    def message
      super + ": [" + @targets.reverse.join(' => ') + "]"
    end
  end

  ####################################################################
  # A FileList is essentially an array with a few helper methods
  # defined to make file manipulation a bit easier.
  #
  # FileLists are lazy.  When given a list of glob patterns for
  # possible files to be included in the file list, instead of
  # searching the file structures to find the files, a FileList holds
  # the pattern for latter use.
  #
  # This allows us to define a number of FileList to match any number of
  # files, but only search out the actual files when then FileList
  # itself is actually used.  The key is that the first time an
  # element of the FileList/Array is requested, the pending patterns
  # are resolved into a real list of file names.
  #
  class FileList 

    include Cloneable

    # == Method Delegation
    #
    # The lazy evaluation magic of FileLists happens by implementing
    # all the array specific methods to call +resolve+ before
    # delegating the heavy lifting to an embedded array object
    # (@items).
    #
    # In addition, there are two kinds of delegation calls.  The
    # regular kind delegates to the @items array and returns the
    # result directly.  Well, almost directly.  It checks if the
    # returned value is the @items object itself, and if so will
    # return the FileList object instead.
    #
    # The second kind of delegation call is used in methods that
    # normally return a new Array object.  We want to capture the
    # return value of these methods and wrap them in a new FileList
    # object.  We enumerate these methods in the +SPECIAL_RETURN+ list
    # below.

    # List of array methods (that are not in +Object+) that need to be
    # delegated.
    ARRAY_METHODS = Array.instance_methods - Object.instance_methods

    # List of additional methods that must be delegated.
    MUST_DEFINE = %w[to_a inspect]

    # List of methods that should not be delegated here (we define
    # special versions of them explicitly below).
    MUST_NOT_DEFINE = %w[to_a to_ary partition *]

    # List of delegated methods that return new array values which
    # need wrapping.
    SPECIAL_RETURN = %w[
      map collect sort sort_by select find_all reject grep
      compact flatten uniq values_at
      + - & |
    ]
    
    DELEGATING_METHODS = (ARRAY_METHODS + MUST_DEFINE - MUST_NOT_DEFINE).sort.uniq
    
    # Now do the delegation.
    DELEGATING_METHODS.each_with_index do |sym, i|
      if SPECIAL_RETURN.include?(sym)
        ln = __LINE__+1
        class_eval %{
          def #{sym}(*args, &block)
            resolve if @pending
            result = @items.send(:#{sym}, *args, &block)
            FileList.new.import(result)
          end
        }, __FILE__, ln
      else
        ln = __LINE__+1
        class_eval %{
          def #{sym}(*args, &block)
            resolve if @pending
            result = @items.send(:#{sym}, *args, &block)
            result.object_id == @items.object_id ? self : result
          end
        }, __FILE__, ln
      end
    end

    # Create a file list from the globbable patterns given.  If you
    # wish to perform multiple includes or excludes at object build
    # time, use the "yield self" pattern.
    #
    # Example:
    #   file_list = FileList.new['lib/**/*.rb', 'test/test*.rb']
    #
    #   pkg_files = FileList.new['lib/**/*'] do |fl|
    #     fl.exclude(/\bCVS\b/)
    #   end
    #
    def initialize(*patterns)
      @pending_add = []
      @pending = false
      @exclude_patterns = DEFAULT_IGNORE_PATTERNS.dup
      @exclude_re = nil
      @items = []
      patterns.each { |pattern| include(pattern) }
      yield self if block_given?
    end

    # Add file names defined by glob patterns to the file list.  If an
    # array is given, add each element of the array.
    #
    # Example:
    #   file_list.include("*.java", "*.cfg")
    #   file_list.include %w( math.c lib.h *.o )
    #
    def include(*filenames)
      # TODO: check for pending
      filenames.each do |fn|
	if fn.respond_to? :to_ary
	  include(*fn.to_ary)
	else
	  @pending_add << fn
	end
      end
      @pending = true
      self
    end
    alias :add :include 
    
    # Register a list of file name patterns that should be excluded
    # from the list.  Patterns may be regular expressions, glob
    # patterns or regular strings.
    #
    # Note that glob patterns are expanded against the file system.
    # If a file is explicitly added to a file list, but does not exist
    # in the file system, then an glob pattern in the exclude list
    # will not exclude the file.
    #
    # Examples:
    #   FileList['a.c', 'b.c'].exclude("a.c") => ['b.c']
    #   FileList['a.c', 'b.c'].exclude(/^a/)  => ['b.c']
    #
    # If "a.c" is a file, then ...
    #   FileList['a.c', 'b.c'].exclude("a.*") => ['b.c']
    #
    # If "a.c" is not a file, then ...
    #   FileList['a.c', 'b.c'].exclude("a.*") => ['a.c', 'b.c']
    #
    def exclude(*patterns)
      patterns.each do |pat| @exclude_patterns << pat end
      if ! @pending
        calculate_exclude_regexp
        reject! { |fn| fn =~ @exclude_re }
      end
      self
    end

    
    # Clear all the exclude patterns so that we exclude nothing.
    def clear_exclude
      @exclude_patterns = []
      calculate_exclude_regexp if ! @pending
    end

    # Define equality.
    def ==(array)
      to_ary == array
    end

    # Return the internal array object.
    def to_a
      resolve
      @items
    end

    # Return the internal array object.
    def to_ary
      resolve
      @items
    end

    # Redefine * to return either a string or a new file list.
    def *(other)
      result = @items * other
      case result
      when Array
	FileList.new.import(result)
      else
	result
      end
    end

    # Resolve all the pending adds now.
    def resolve
      if @pending
        @pending = false
        @pending_add.each do |fn| resolve_add(fn) end
        @pending_add = []
        resolve_exclude
      end
      self
    end

    def calculate_exclude_regexp
      ignores = []
      @exclude_patterns.each do |pat|
        case pat
        when Regexp
          ignores << pat
        when /[*.]/
          Dir[pat].each do |p| ignores << p end
        else
          ignores << Regexp.quote(pat)
        end
      end
      if ignores.empty?
        @exclude_re = /^$/
      else
        re_str = ignores.collect { |p| "(" + p.to_s + ")" }.join("|")
        @exclude_re = Regexp.new(re_str)
      end
    end

    def resolve_add(fn)
      case fn
      when Array
        fn.each { |f| self.resolve_add(f) }
      when %r{[*?]}
        add_matching(fn)
      else
        self << fn
      end
    end
    private :resolve_add

    def resolve_exclude
      @exclude_patterns.each do |pat|
        case pat
        when Regexp
          reject! { |fn| fn =~ pat }
        when /[*.]/
          reject_list = Dir[pat]
          reject! { |fn| reject_list.include?(fn) }
        else
          reject! { |fn| fn == pat }
        end
      end
      self
    end
    private :resolve_exclude

    # Return a new FileList with the results of running +sub+ against
    # each element of the oringal list.
    #
    # Example:
    #   FileList['a.c', 'b.c'].sub(/\.c$/, '.o')  => ['a.o', 'b.o']
    #
    def sub(pat, rep)
      inject(FileList.new) { |res, fn| res << fn.sub(pat,rep) }
    end

    # Return a new FileList with the results of running +gsub+ against
    # each element of the original list.
    #
    # Example:
    #   FileList['lib/test/file', 'x/y'].gsub(/\//, "\\")
    #      => ['lib\\test\\file', 'x\\y']
    #
    def gsub(pat, rep)
      inject(FileList.new) { |res, fn| res << fn.gsub(pat,rep) }
    end

    # Same as +sub+ except that the oringal file list is modified.
    def sub!(pat, rep)
      each_with_index { |fn, i| self[i] = fn.sub(pat,rep) }
      self
    end

    # Same as +gsub+ except that the original file list is modified.
    def gsub!(pat, rep)
      each_with_index { |fn, i| self[i] = fn.gsub(pat,rep) }
      self
    end

    # Apply the pathmap spec to each of the included file names,
    # returning a new file list with the modified paths.  (See
    # String#pathmap for details.)
    def pathmap(spec=nil)
      collect { |fn| fn.pathmap(spec) }
    end

    # Return a new array with <tt>String#ext</tt> method applied to
    # each member of the array.
    #
    # This method is a shortcut for:
    #
    #    array.collect { |item| item.ext(newext) }
    #
    # +ext+ is a user added method for the Array class.
    def ext(newext='')
      collect { |fn| fn.ext(newext) }
    end


    # Grep each of the files in the filelist using the given pattern.
    # If a block is given, call the block on each matching line,
    # passing the file name, line number, and the matching line of
    # text.  If no block is given, a standard emac style
    # file:linenumber:line message will be printed to standard out.
    def egrep(pattern)
      each do |fn|
	open(fn) do |inf|
	  count = 0
	  inf.each do |line|
	    count += 1
	    if pattern.match(line)
	      if block_given?
		yield fn, count, line
	      else
		puts "#{fn}:#{count}:#{line}"
	      end		
	    end
	  end
	end
      end
    end

    # FileList version of partition.  Needed because the nested arrays
    # should be FileLists in this version.
    def partition(&block)	# :nodoc:
      resolve
      result = @items.partition(&block)
      [
        FileList.new.import(result[0]),
        FileList.new.import(result[1]),
      ]
    end
    
    # Convert a FileList to a string by joining all elements with a space.
    def to_s
      resolve if @pending
      self.join(' ')
    end

    # Add matching glob patterns.
    def add_matching(pattern)
      Dir[pattern].each do |fn|
        self << fn unless exclude?(fn)
      end
    end
    private :add_matching

    # Should the given file name be excluded?
    def exclude?(fn)
      calculate_exclude_regexp unless @exclude_re
      fn =~ @exclude_re
    end

    DEFAULT_IGNORE_PATTERNS = [
      /(^|[\/\\])CVS([\/\\]|$)/,
      /(^|[\/\\])\.svn([\/\\]|$)/,
      /\.bak$/,
      /~$/,
      /(^|[\/\\])core$/
    ]
    @exclude_patterns = DEFAULT_IGNORE_PATTERNS.dup

    def import(array)
      @items = array
      self
    end

    class << self
      # Create a new file list including the files listed. Similar to:
      #
      #   FileList.new(*args)
      def [](*args)
        new(*args)
      end

      # Set the ignore patterns back to the default value.  The
      # default patterns will ignore files 
      # * containing "CVS" in the file path
      # * containing ".svn" in the file path
      # * ending with ".bak"
      # * ending with "~"
      # * named "core"
      #
      # Note that file names beginning with "." are automatically
      # ignored by Ruby's glob patterns and are not specifically
      # listed in the ignore patterns.
      def select_default_ignore_patterns
        @exclude_patterns = DEFAULT_IGNORE_PATTERNS.dup
      end

      # Clear the ignore patterns.  
      def clear_ignore_patterns
        @exclude_patterns = [ /^$/ ]
      end
    end
  end # FileList
end

module Rake
  class << self

    # Yield each file or directory component.
    def each_dir_parent(dir)
      old_length = nil
      while dir != '.' && dir.length != old_length
	yield(dir)
	old_length = dir.length
	dir = File.dirname(dir)
      end
    end
  end
end

# Alias FileList to be available at the top level.
FileList = Rake::FileList

######################################################################
module Rake

  # Default Rakefile loader used by +import+.
  class DefaultLoader
    def load(fn)
      Kernel.load(File.expand_path(fn))
    end
  end

  # EarlyTime is a fake timestamp that occurs _before_ any other time
  # value.
  class EarlyTime
    include Comparable
    include Singleton

    def <=>(other)
      -1
    end

    def to_s
      "<EARLY TIME>"
    end
  end

  EARLY = EarlyTime.instance
end

######################################################################
# Extensions to time to allow comparisons with an early time class.
#
class Time
  alias rake_original_time_compare :<=>
  def <=>(other)
    if Rake::EarlyTime === other
      - other.<=>(self)
    else
      rake_original_time_compare(other)
    end
  end     
end

module Rake

  ####################################################################
  # The NameSpace class will lookup task names in the the scope
  # defined by a +namespace+ command.
  #
  class NameSpace

    # Create a namespace lookup object using the given task manager
    # and the list of scopes.
    def initialize(task_manager, scope_list)
      @task_manager = task_manager
      @scope = scope_list.dup
    end
    
    # Lookup a task named +name+ in the namespace.
    def [](name)
      @task_manager.lookup(name, @scope)
    end
  end


  ####################################################################
  # The TaskManager module is a mixin for managing tasks.  
  module TaskManager
    # Track the last comment made in the Rakefile.
    attr_accessor :last_comment

    def initialize
      super
      @tasks = Hash.new
      @rules = Array.new
      @scope = Array.new
      @last_comment = nil
    end

    def create_rule(args, &block)
      pattern, deps = resolve_args(args)
      pattern = Regexp.new(Regexp.quote(pattern) + '$') if String === pattern
      @rules << [pattern, deps, block]
    end

    def define_task(task_class, args, &block)
      task_name, deps = resolve_args(args)
      task_name = task_class.scope_name(@scope, task_name)
      deps = [deps] unless deps.respond_to?(:to_ary)
      deps = deps.collect {|d| d.to_s }
      task = intern(task_class, task_name)
      task.application = self
      task.add_comment(@last_comment)
      @last_comment = nil
      task.enhance(deps, &block)
      task
    end

    # Lookup a task.  Return an existing task if found, otherwise
    # create a task of the current type.
    def intern(task_class, task_name)
      @tasks[task_name.to_s] ||= task_class.new(task_name, self)
    end

    # Find a matching task for +task_name+.  
    def [](task_name, scopes=nil)
      task_name = task_name.to_s
      self.lookup(task_name, scopes) or
	enhance_with_matching_rule(task_name) or
	synthesize_file_task(task_name) or
	fail "Don't know how to build task '#{task_name}'"
    end

    def synthesize_file_task(task_name)
      return nil unless File.exist?(task_name)
      define_task(Rake::FileTask, task_name)
    end
    
    # Resolve the arguments for a task/rule.
    def resolve_args(args)
      case args
      when Hash
	fail "Too Many Task Names: #{args.keys.join(' ')}" if args.size > 1
	fail "No Task Name Given" if args.size < 1
	task_name = args.keys[0]
	deps = args[task_name]
	deps = [deps] if (String===deps) || (Regexp===deps) || (Proc===deps)
      else
	task_name = args
	deps = []
      end
      [task_name, deps]
    end
    
    # If a rule can be found that matches the task name, enhance the
    # task with the prerequisites and actions from the rule.  Set the
    # source attribute of the task appropriately for the rule.  Return
    # the enhanced task or nil of no rule was found.
    def enhance_with_matching_rule(task_name, level=0)
      fail Rake::RuleRecursionOverflowError,
	"Rule Recursion Too Deep" if level >= 16
      @rules.each do |pattern, extensions, block|
	if md = pattern.match(task_name)
	  task = attempt_rule(task_name, extensions, block, level)
	  return task if task
	end
      end
      nil
    rescue Rake::RuleRecursionOverflowError => ex
      ex.add_target(task_name)
      fail ex
    end
    
    # List of all defined tasks in this application.
    def tasks
      @tasks.values.sort_by { |t| t.name }
    end

    # Clear all tasks in this application.
    def clear
      @tasks.clear
      @rules.clear
    end

    # Lookup a task, using scope and the scope hints in the task name.
    # This method performs straight lookups without trying to
    # synthesize file tasks or rules.  Special scope names (e.g. '^')
    # are recognized.  If no scope argument is supplied, use the
    # current scope.  Return nil if the task cannot be found.
    def lookup(task_name, initial_scope=nil)
      initial_scope ||= @scope
      task_name = task_name.to_s
      if task_name =~ /^rake:/
	scopes = []
	task_name = task_name.sub(/^rake:/, '')
      elsif task_name =~ /^(\^+)/
	scopes = initial_scope[0, initial_scope.size - $1.size]
	task_name = task_name.sub(/^(\^+)/, '')
      else
	scopes = initial_scope
      end
      lookup_in_scope(task_name, scopes)
    end

    # Lookup the task name 
    def lookup_in_scope(name, scope)
      n = scope.size
      while n >= 0
	tn = (scope[0,n] + [name]).join(':')
	task = @tasks[tn]
	return task if task
	n -= 1
      end
      nil
    end
    private :lookup_in_scope

    # Return the list of scope names currently active in the task
    # manager.
    def current_scope
      @scope.dup
    end

    # Evaluate the block in a nested namespace named +name+.  Create
    # an anonymous namespace if +name+ is nil.
    def in_namespace(name)
      name ||= generate_name
      @scope.push(name)
      ns = NameSpace.new(self, @scope)
      yield(ns)
      ns
    ensure
      @scope.pop
    end

    private

    # Generate an anonymous namespace name.
    def generate_name
      @seed ||= 0
      @seed += 1
      "_anon_#{@seed}"
    end

    # Attempt to create a rule given the list of prerequisites.
    def attempt_rule(task_name, extensions, block, level)
      sources = make_sources(task_name, extensions)
      prereqs = sources.collect { |source|
	if File.exist?(source) || Rake::Task.task_defined?(source)
	  source
	elsif parent = enhance_with_matching_rule(sources.first, level+1)
	  parent.name
	else
	  return nil
	end
      }
      task = FileTask.define_task({task_name => prereqs}, &block)
      task.sources = prereqs
      task
    end
    
    # Make a list of sources from the list of file name extensions /
    # translation procs.
    def make_sources(task_name, extensions)
      extensions.collect { |ext|
	case ext
	when String
	  task_name.sub(/\.[^.]*$/, ext)
	when Proc
	  ext.call(task_name)
	else
	  fail "Don't know how to handle rule dependent: #{ext.inspect}"
	end
      }.flatten
    end
    
  end

  ######################################################################
  # Rake main application object.  When invoking +rake+ from the
  # command line, a Rake::Application object is created and run.
  #
  class Application
    include TaskManager

    # The original directory where rake was invoked.
    attr_reader :original_dir

    RAKEFILES = ['rakefile', 'Rakefile', 'rakefile.rb', 'Rakefile.rb']
    
    OPTIONS = [
      ['--dry-run',  '-n', GetoptLong::NO_ARGUMENT,
	"Do a dry run without executing actions."],
      ['--help',     '-H', GetoptLong::NO_ARGUMENT,
	"Display this help message."],
      ['--libdir',   '-I', GetoptLong::REQUIRED_ARGUMENT,
	"Include LIBDIR in the search path for required modules."],
      ['--rakelibdir', '-R', GetoptLong::REQUIRED_ARGUMENT,
	"Auto-import any .rake files in RAKELIBDIR. (default is 'rakelib')"],
      ['--nosearch', '-N', GetoptLong::NO_ARGUMENT,
	"Do not search parent directories for the Rakefile."],
      ['--prereqs',  '-P', GetoptLong::NO_ARGUMENT,
	"Display the tasks and dependencies, then exit."],
      ['--quiet',    '-q', GetoptLong::NO_ARGUMENT,
	"Do not log messages to standard output."],
      ['--rakefile', '-f', GetoptLong::OPTIONAL_ARGUMENT,
	"Use FILE as the rakefile."],
      ['--require',  '-r', GetoptLong::REQUIRED_ARGUMENT,
	"Require MODULE before executing rakefile."],
      ['--silent',   '-s', GetoptLong::NO_ARGUMENT,
	"Like --quiet, but also suppresses the 'in directory' announcement."],
      ['--tasks',    '-T', GetoptLong::OPTIONAL_ARGUMENT,
	"Display the tasks (matching optional PATTERN) with descriptions, then exit."],
      ['--trace',    '-t', GetoptLong::NO_ARGUMENT,
	"Turn on invoke/execute tracing, enable full backtrace."],
      ['--usage',    '-h', GetoptLong::NO_ARGUMENT,
	"Display usage."],
      ['--verbose',  '-v', GetoptLong::NO_ARGUMENT,
	"Log message to standard output (default)."],
      ['--version',  '-V', GetoptLong::NO_ARGUMENT,
	"Display the program version."],
      ['--classic-namespace', '-C', GetoptLong::NO_ARGUMENT,
	"Put Task and FileTask in the top level namespace"],
    ]
    
    # Create a Rake::Application object.
    def initialize
      super
      @rakefile = nil
      @pending_imports = []
      @imported = []
      @loaders = {}
      @default_loader = Rake::DefaultLoader.new
      @original_dir = Dir.pwd
      add_loader('rf', DefaultLoader.new)
      add_loader('rake', DefaultLoader.new)
    end
    
    # Application options from the command line
    def options
      @options ||= OpenStruct.new
    end

    # True if one of the files in RAKEFILES is in the current directory.
    # If a match is found, it is copied into @rakefile.
    def have_rakefile
      RAKEFILES.each do |fn|
	if File.exist?(fn) || fn == ''
	  @rakefile = fn
	  return true
	end
      end
      return false
    end
    
    # Display the program usage line.
    def usage
      puts "rake [-f rakefile] {options} targets..."
    end
    
    # Display the rake command line help.
    def help
      usage
      puts
      puts "Options are ..."
      puts
      OPTIONS.sort.each do |long, short, mode, desc|
	if mode == GetoptLong::REQUIRED_ARGUMENT
	  if desc =~ /\b([A-Z]{2,})\b/
	    long = long + "=#{$1}"
	  end
	end
	printf "  %-20s (%s)\n", long, short
	printf "      %s\n", desc
      end
    end
    
    # Display the tasks and dependencies.
    def display_tasks_and_comments
      displayable_tasks = Rake::Task.tasks.select { |t|
	t.comment && t.name =~ options.show_task_pattern
      }
      width = displayable_tasks.collect { |t|
	t.name.length
      }.max
      displayable_tasks.each do |t|
	printf "rake %-#{width}s  # %s\n", t.name, t.comment
      end
    end
    
    # Display the tasks and prerequisites
    def display_prerequisites
      Rake::Task.tasks.each do |t|
	puts "rake #{t.name}"
	t.prerequisites.each { |pre| puts "    #{pre}" }
      end
    end
    
    # Return a list of the command line options supported by the
    # program.
    def command_line_options
      OPTIONS.collect { |lst| lst[0..-2] }
    end
    
    # Do the option defined by +opt+ and +value+.
    def do_option(opt, value)
      case opt
      when '--dry-run'
	verbose(true)
	nowrite(true)
	options.dryrun = true
	options.trace = true
      when '--help'
	help
	exit
      when '--libdir'
	$:.push(value)
      when '--nosearch'
	options.nosearch = true
      when '--prereqs'
	options.show_prereqs = true
      when '--quiet'
	verbose(false)
      when '--rakefile'
	RAKEFILES.clear
	RAKEFILES << value
      when '--rakelibdir'
	options.rakelib = value.split(':')
      when '--require'
        begin
          require value
        rescue LoadError => ex
          begin
            rake_require value
          rescue LoadError => ex2
            raise ex
          end
        end
      when '--silent'
	verbose(false)
	options.silent = true
      when '--tasks'
	options.show_tasks = true
	options.show_task_pattern = Regexp.new(value || '.')
      when '--trace'
	options.trace = true
	verbose(true)
      when '--usage'
	usage
	exit
      when '--verbose'
	verbose(true)
      when '--version'
	puts "rake, version #{RAKEVERSION}"
	exit
      when '--classic-namespace'
	require 'rake/classic_namespace'
	options.classic_namespace = true
      else
	fail "Unknown option: #{opt}"
      end
    end
    
    # Read and handle the command line options.
    def handle_options
      options.rakelib = 'rakelib'

      opts = GetoptLong.new(*command_line_options)
      opts.each { |opt, value| do_option(opt, value) }

      # If class namespaces are requested, set the global options
      # according to the values in the options structure.
      if options.classic_namespace
	$show_tasks = options.show_tasks
	$show_prereqs = options.show_prereqs
	$trace = options.trace
	$dryrun = options.dryrun
	$silent = options.silent
      end
    end
    
    # Similar to the regular Ruby +require+ command, but will check
    # for .rake files in addition to .rb files.
    def rake_require(file_name, paths=$LOAD_PATH, loaded=$")
      return false if loaded.include?(file_name)
      paths.each do |path|
        fn = file_name + ".rake"
        full_path = File.join(path, fn)
        if File.exist?(full_path)
          load full_path
          loaded << fn
          return true
        end
      end
      fail LoadError, "Can't find #{file_name}"
    end

    # Find the rakefile and then load it and any pending imports.
    def load_rakefile
      here = Dir.pwd
      while ! have_rakefile
	Dir.chdir("..")
	if Dir.pwd == here || options.nosearch
	  fail "No Rakefile found (looking for: #{RAKEFILES.join(', ')})"
	end
	here = Dir.pwd
      end
      puts "(in #{Dir.pwd})" unless options.silent
      $rakefile = @rakefile
      load File.expand_path(@rakefile) if @rakefile != ''
      options.rakelib.each do |rlib|
	Dir["#{rlib}/*.rake"].each do |name| add_import name end
      end
      load_imports
    end
    
    # Collect the list of tasks on the command line.  If no tasks are
    # give, return a list containing only the default task.
    # Environmental assignments are processed at this time as well.
    def collect_tasks
      tasks = []
      ARGV.each do |arg|
	if arg =~ /^(\w+)=(.*)$/
	  ENV[$1] = $2
	else
	  tasks << arg
	end
      end
      tasks.push("default") if tasks.size == 0
      tasks
    end
    
    # Add a file to the list of files to be imported.
    def add_import(fn)
      @pending_imports << fn
    end
    
    # Load the pending list of imported files.
    def load_imports
      while fn = @pending_imports.shift
	next if @imported.member?(fn)
	Rake::Task[fn].invoke if Rake::Task.task_defined?(fn)
	ext = File.extname(fn)
	loader = @loaders[ext] || @default_loader
	loader.load(fn)
	@imported << fn
      end
    end
    
    # Add a loader to handle imported files ending in the extension
    # +ext+.
    def add_loader(ext, loader)
      ext = ".#{ext}" unless ext =~ /^\./
      @loaders[ext] = loader
    end
    
    # Warn about deprecated use of top level constant names.
    def const_warning(const_name)
      @const_warning ||= false
      if ! @const_warning
	puts %{WARNING: Deprecated reference to top-level constant '#{const_name}'} +
	  %{found at: #{rakefile_location}} # '
	puts %{    Use --classic-namespace on rake command}
	puts %{    or 'require "rake/classic_namespace"' in Rakefile}
      end
      @const_warning = true
    end

    def rakefile_location
      begin
	fail
      rescue RuntimeError => ex
	ex.backtrace.find {|str| str =~ /#{@rakefile}/ } || ""
      end
    end

    # Run the +rake+ application.
    def run
      handle_options
      begin
	tasks = collect_tasks
	load_rakefile
	if options.show_tasks
	  display_tasks_and_comments
	elsif options.show_prereqs
	  display_prerequisites
	else
	  tasks.each { |task_name| Rake::Task[task_name].invoke }
	end
      rescue Exception => ex
	puts "rake aborted!"
	puts ex.message
	if options.trace
	  puts ex.backtrace.join("\n")
	else
	  puts ex.backtrace.find {|str| str =~ /#{@rakefile}/ } || ""
	  puts "(See full trace by running task with --trace)"
	end
	exit(1)
      end    
    end
  end
end


class Module
  # Rename the original handler to make it available.
  alias :rake_original_const_missing :const_missing
  
  # Check for deprecated uses of top level (i.e. in Object) uses of
  # Rake class names.  If someone tries to reference the constant
  # name, display a warning and return the proper object.  Using the
  # --classic-namespace command line option will define these
  # constants in Object and avoid this handler.
  def const_missing(const_name)
    case const_name
    when :Task
      Rake.application.const_warning(const_name)
      Rake::Task
    when :FileTask
      Rake.application.const_warning(const_name)
      Rake::FileTask
    when :FileCreationTask
      Rake.application.const_warning(const_name)
      Rake::FileCreationTask
    when :RakeApp
      Rake.application.const_warning(const_name)
      Rake::Application
    else
      rake_original_const_missing(const_name)
    end
  end
end

if __FILE__ == $0 then
  Rake::Application.new.run
end